JPA, How to use the same class (entity) to map different tables?

Question

I have two tables: Ta and Tb. They have exactly the same table structure but different table names.

I try to create one entity class to map

Answer 1

You can also do this without using subclasses if you use two different persistence units.

Each persistence unit can specify a unique set of mappings (including table name). One way to achieve this is to create two orm.xml files. In persistence.xml you'll need something like this :

     
        . . .
        orm-1.xml
        . . .
    

     
        . . .
        orm-2.xml
        . . .
    

Then within orm-1.xml :

    mypackage
    
        
    

And within orm-2.xml :

    mypackage
    
        
    

You'll need to create a separate EntityManagerFactory for each PersistenceUnit (probably not what you want), but if you wanted to use the same class on different databases (with different table names) this would be a way to go.